Engraving machine



Apr. 24, 1923. 1,452,858 R. WETZER ET AL ENGRAVING MACHINE Filed Aug. 11, 1921 3 'Sheets-Sheet 1 Q Q EL@ Mahne@ Machine @www y @ff Fzyff NVKENTORS Rud'of WeTzer Curd Nube.

Yhelr HTTO R N EY.

Apr. 24, 1923.

8 5 .m u n w A ..w n, 1 w h s 5. 1 .L l Amm j I uw, @mu l zmwn TVA amd wm .Ei uw?, F R ma l Patented Apr., 24, 1923.

UNITE ,lf TES tinte caries.-

RUDoLr wnfrznit, or PFRONTEN, AND cuan Nunn, or oFrENBAcH-oN-THE-MAIN, GERMANY.

ENGRAVING MACHINE.

Application filed August 11, 1921.

To all whom it may concern.' f

Be it known that we, RUDOLF VETZER and CURD Nunn, citizens of Germany, residing respectively at Pfronten, Bavaria, and Offenbach-on-the-Main, Hesse, Germany, have invented certain new and useful Improvements in Engraving Machines (for which we have filed application in Germany on May 22, 1919, Patent No. 318,882, dated May 23, 1919) and we do hereby declare the following to be a full, clear, and exact description of the invent-ion such as will enable others skilled in the art to which it appertains to make and use the same.

Our invention relates to improvements in engraving machines of the type in which the tracing pencil is suspended so as to be capable of swinging in all directions and is connected with an arm carrying the engraving-tool, and the object'of our invention is to provide certain changes in the construction of these machines, as hereinafter set forth, with a View of eliminating certain disadvantages inhering in machines of the class referred to.

In describing our invention we refer to the drawing herewith in which Figures 1, 2, 3 and 4g are examples of the relative arrangement of letters, as produced by the employment of the old machines of the type referred to and, in comparison therewith, show the character of such arrangement attainable with machines improvedv as herein set forth. Figure 5 is a front-view of my improved construction and Figure 6 aplan or top-view of the same. Figures 7, 8 and 9 are diagrams illustrating the arrangement and action -of certain parts of the machine hereinafter more particularly referredA to. Figure 10 is a plan` ortop-viewof a somewhat modied construction of our improved machine, likewise hereinafter more particularly referred to. Figure 11 illustrates letters obtainable by the employment of our improvements, also referred to hereinbelow. Figure 12l is a diagram in transverse section on the line mof Figure 6 and will be 4likewise-hereinafter referred to. Figures 13, 14, 15 of which Figures 13 and 14 correspond with Figures 5 and 6, illustrate a modified though within the spirit andscope of our inf vention, ywhere three engraving spindles havebeenfprovided instead of one. Fig. 16

construction` of our machine,

Serial No. 491,357.

is an elevational view of a further modified form of the invention; Fig. 17 is a detail in side elevation of the arm carrying the engraving tool, and Fig. 18 is a diagram hereinafter referred to.

Inthe engravings made with engraving machines, as constructed heretofore, the height of the letters would always bear a certain proportion to the width of the letters and rthat proportion would correspond with the original "pattern or stencil plate.

As a* consequence it would frequently occur, for instance, in cases where small shields were to be made which were not to exceed a certain length, that the engraving had to be in very small type, as shown byj way of example in Figure 1 of the drawing herewith, while in order to be more distinct the types in a shield of the same length should be somewhathigher, as indicated inFigure 2. The case would be reversed in the example illustrated by Figure 3 where the letters, to make a better appearance, if of the same height should be greater in width, as shown in Figure 4.

With a view of overcoming this disadvantage `we design the hereinafter described engraving-machine on the swinging-system'` which permits of producing with the same stencil-plate types distorted in the sense' indicated.y `I

In machines of the class alluded to,fas in use heretofore, a tubular rod 7s lis provided, suspended, swinging in all directions from a universal joint U2, the said rod carrying a telescopically movable tracing-pencil L vand being attached by means of a movable and adjustable sleeve 0 to an arm comprising two members m, Z of which the member Z carriesthe engraver Gcwhich may be a chisel orl cutter. The members m and Z may be jointed to -each other at as.

In our invention the said rod 7c which serves for the tracing of the stencil-pattern, is not directly connected to the arm m, l, but through the medium of another tubular rod g which is also suspended swingingly in all directions by means-of ay universal joint U1.y Bothf rods 7c, g are'connected witheach other by a guiding bar or plate n which has one end connected at n, with a sleeve e, movable and adjustable ony the rod g, and the other end connected at n2 with the movable and adjustable sleeve o on the rod 7c. The arm ico m, Z has its member lml connected to the sleeve a at m1.

The device, as described, operates in the following way: YWhen the distance between the working points nl and n2 of the bar or plate n is, as shown in Figures 5 and 7, equal to the distance between the suspending points of the rods g and la, the transfer of the stencil-pattern S traced by the pencil 7b takes place' in the same proportion and exactly in the same way as if the rod g carried the tracing pencil.

If, however, the said distances are unequal as, for instance, when the sleeve o is, as shown in Figure 8, moved upward on the rod towards the universal joint U2, only those of the lines traced by the pencil it will be transferred in the proportion of the stencilpattern which are perpendicular to the plane of the sheet of drawing containing Figure 5, indicated in Figure G by an arrow in full lines, while all other lines which are in the direction of the arrows shown in Figures 5 and 8 in dotted lines, are transferred shortened, the shortening being the greater the nearer the sleeve o is to the universal joint U2.

When the sleeve 0 is, as shown in Figure 9, moved downward on the rod 7c, the result will be just the reverse. The lineswhich were previously transferred shorter will now be transferred longer.

During the movement perpendicular to the plane of the sheet of drawing containing` Figures 7, 8, 9 the members g, 7c, n, act as if they were rigidly connected and, therefore, in all these cases the movement from o will be the same as if the pencil 7L. were attached to the rod g.

A somewhat modified construction is illustra'ted in a plan or top-view in Figure 10. In this construction the rods la and g are not suspended from separate `universal joints. rIhe two rods in this case are supported in the frame B at e and c so as to be capable of swinging in the same direction in the frame R which, in turn, is swingingly supported at d transverse to the swinging direction of the rods g and lc.

In practically carrying out our invention the following should be noticed in addition to what has been set forth herein with respect to the production of distorted letters,

as illustrated in Figures 1 to 4E: In usingk stencil-plates of the customary size there is room in the stencil-plate-holder for about twenty letters only. By decreasing the width of the stencilnplates in proportion to their height, as illustrated by the let-tersmarlred a and 7) in Figure 11, there will be ample room in the said holder for 30 letters. By using the position of the sleeve o shown in Figure 9 the width of the letters will by the transfer be enlarged and accordingly the engraving appear normal. i

In all engraving machines of the class referred to distortions are, as hereinafter explained, liable to occur in as much as strokes perpendicular to the plane of the sheet of drawing containing Figure 5 do not become precisely parallel, when they are drawn in the middle and on the two sides of the pattern-holder S, and to correct such distortions and compensate therefore we provide in the forepart of the arm m a slot s wherein a pencil or point r may be moved back and forth and held in adjusted position as indicated in Fig. 17. Following is a description of the operation of this part of the invention.

Assuming the point 7" to be in the plane indicated by the line m-m in Fig, 6, with every movement of the tracing-pencil L the point m, (Figure 5) moves on an imaginary ball-cup the center of which is identical with the rcenter of the universal joint U1. Accordingly, this point ascends whenever the tracing-pin It is brought out of its particular position and the farther the movement of the said pin 7L extends and the larger the radius of the imaginary sphere U1, m1 is, the larger is the engraving. The distance from m] to the point of the cutter being invariable however, the cutter will, whenever the pencil Il moves in perpendicular direction to the plane of the sheet containing Figure 5, have j to make a movement which somewhat diverges from the straight line, as shown, greatly exaggerated in full lines in Figure 18.

Now, when the pencil is not, as assumed and as shown in Figure 6, in the line .fr-az, but is moved rearwardly thereof as shown in Figure 17, which is a side-view, the raising and lowering of the fulcrum would with the above-mentioned movement of the pencil h cause the distortion shown in dotted lines in Figure 18, if the distortion just described and shown in full lines in Figure 18 would not at the same time come out. It will be thus understood that the two distortions inthe forepart compensate each other if they are of corresponding extent.

Now, the area which is covered by the tracing-pin h is so positioned that only that portion is used in which those distortions do compensate each other.

It will be clear from the foregoin that by a suitable adjustment ofthe penci 'l' for each respective size of the cut, the distortion may be made to disappear. The larger the engraving desired, the more should the pencil r be taken back.

For the manufacture of articles in quantities I prefer the modiied construction shown in Figures 13, 14, 15. In this modification there may be provided a plurality, say three spindles each of which may be adjusted for a working-piece, independent ofv the others by a movement and swing about the pin p or, g. While in Figure 14 the three spindles are supposed to work in one line, in Figure l5 one of the spindles, for example the one on the left side, is moved forward and the one on the right side is swung aside at a suitable angle.

In the modification illustrated in Figure 16 the sleeve z is not movable on its rod, but is rigidly attached thereto. But the rod g, with the sleeve a thereon, is movable with the sleeve or collar t provided in the joint U1, and may be made secure in any position. This arrangement permits of an increased scope of use of the machine, inasmuch as larger objects intended to be engraved upon are not obstructed by the lower portion of the rod g, as would be the case with the form illustrated in Figure 5.

We claim 1. An engraving machine, including a pair of normally parallel freely movable suspended members, one of said members adapted to carry a tracing point, a tool holder movably connected to the other of said members, and means interconnecting said members and adjustable to vary the relative position of said members to one another.

2. An engraving machine, including a pair of freely movable suspended members, one oi" said members adapted to carry a tracing point, a sleeve on each member, means engaging said sleeves for adjust-ably connecting said members to one another, a tool holder, and means for movably connecting the tool holder to the sleeve ofthe member not carrying the tracing point.

3. An engraving machine, including a pair of normally parallel supports, universal `joints in which said supports are suspended, means interconnecting said supports and adapted to vary the angular relamembers, one of said members adapted toy carry a tracing point, a tool holder, an arm movably connecting said tool holder Lto the movable member not carrying the tracing point, said arm having a slot therein, and a pencil adjustable in said slot to compensate for the tendency of the machine to distort letters during the engraving operation.

In testimony whereof we hereunto aiiix our signatures in the presence of two witnesses.

RUDOLF lVETZER. CURD NUB-E.

Witnesses ALB. WEICKMAN,

L. KoLB. 

